After I start my 01 c240 and ready to go, as soon as I step on the gas pedal the car is not moving, even I step the gas pedal all the way to the floor the rpm is not respond and it delay for 5 and more seconds then it does up and the car is start moving forward. I visited my mechanic and his computer shown a code "PO120" Throttle/Pedal Position Sensor Circuit". I tried to reset the sensor as per other friends posted at the forum but it didn't work. Can any friends able to help me out what I should do? Can I DIY to replace the sensor by myself? How much will it cost? Where is the sensor located it? It is very very dangerous to drive this car on the road because it delay to start moving the car after it stop in front of the stop sign or traffic light. I am very frustrate now. I just bought it not too long ago! Please help!